1. Field of the Invention
The present invention relates to a 3D endoscope for three-dimensionally observing an operative site.
2. Description of the Related Art
A 3D endoscope is used to three-dimensionally observe a micro operative site, for example, in surgery within a body cavity. This 3D endoscope has a pair of right and left observation units, and a pair of right and left imaging units corresponding to the observation units. Observation optical systems of the observation units observe the operative site, and imaging optical systems of the imaging units image the operative site. Such a 3D endoscope comprises what is called a stereomicroscope capable of enlarged observation and three-dimensional observation of the operative site.
In the 3D endoscope, the central position of a left image obtained by the left imaging unit and the central position of a right image obtained by the right imaging unit need to correspond to each other at a desired point for the three-dimensional observation. Moreover, the angle of rotation of the left image around the optical axis of the left imaging optical system and the angle of rotation of the right image around the optical axis of the right imaging optical system need to correspond to each other for the three-dimensional observation. Therefore, adjustment members for adjusting the central positions and the angles of rotation are provided around the imaging units.
For example, Jpn. Pat. Appln. KOKAI Publication No. 2001-242521 has disclosed a method of adjusting the central positions and angles of rotation of a pair of right and left images by shifting or rotating an imaging device relative to imaging optical systems.
Furthermore, for example, Japanese Patent No. 4474312 has disclosed a method of providing proper three-dimensional observation by clipping out a range in which the central positions of a pair of right and left images correspond to each other at a desired point in images obtained by imaging units.